The correct answer is 1966. In 1966, the state of Punjab was divided to form the new form the new state of Haryana. The Punjab Reorganization Act was passed by the Indian parliament on 18 September 1966. It led to dissolving the former state of East Punjab. Out of the former East Punjab, the modern state of Punjab was created, the new state of Haryana was created. City of Chandigarh became the provisional capital of both the Punjab and Haryana. Thus, we can say that in 1966, the state of Punjab was divided to form the new state of Haryana.